protected object EvaluateAssignmentExpr(AstAssignmentExpr expr)
{
if (HadErrorOrReturn())
{
return(null);
}
if (expr.m_lhs.m_instance != null)
{
object instanceObj = EvaluateExpr(expr.m_lhs.m_instance);
Instance instance = instanceObj as Instance;
if (instance != null)
{
object value = EvaluateExpr(expr.m_rhs);
if (HadErrorOrReturn())
{
return(null);
}
instance.SetMember(expr.m_lhs.m_identifier.m_identifier, value);
return(value);
}
else
{
m_runtimeError = true;
Lox.Error(expr.m_startLine, "Only class instances can access properties with '.'");
return(null);
}
}
else
{
object value = EvaluateExpr(expr.m_rhs);
if (HadErrorOrReturn())
{
return(null);
}
bool success = m_environment.Assign(expr.m_lhs.m_identifier, value);
if (success)
{
return(value);
}
else
{
m_runtimeError = true;
Lox.Error(expr.m_startLine, "Undefined variable \"" + expr.m_lhs.m_identifier + "\"");
return(null);
}
}
}
protected void ResolveAssignmentExpr(AstAssignmentExpr expr)
{
ResolveExpr(expr.m_rhs);
ResolveVarExpr(expr.m_lhs);
}